Prior to the present invention, function, i.e., waveform, generators have been rack mounted or bench type units, programmable via an appropriate input bus or manually via front panel controls, and have generally been bulky and complex. Moreover, their function generating versatility has been limited. The present invention overcomes these disadvantages in that it is a relatively simple circuit arrangement controlled by a central processing unit via an input bus. The circuitry and techniques inherent in the invention provide wide versatility in the choice of waveform, frequency and amplitude. High resolution of output waveform amplitude is achieved via a novel arrangement of multiplying digital to analog converters and operational amplifiers.